CN112444759B - Open-circuit fault diagnosis method and system for power switch device of three-phase three-level rectifier - Google Patents
Open-circuit fault diagnosis method and system for power switch device of three-phase three-level rectifier Download PDFInfo
- Publication number
- CN112444759B CN112444759B CN202011245559.2A CN202011245559A CN112444759B CN 112444759 B CN112444759 B CN 112444759B CN 202011245559 A CN202011245559 A CN 202011245559A CN 112444759 B CN112444759 B CN 112444759B
- Authority
- CN
- China
- Prior art keywords
- phase
- diagnosis
- fault
- current
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/54—Testing for continuity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
- G01R19/16533—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the application
- G01R19/16557—Logic probes, i.e. circuits indicating logic state (high, low, O)
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/40—Testing power supplies
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Rectifiers (AREA)
Abstract
The invention discloses a fault diagnosis method and a fault diagnosis system for a three-phase three-level rectifier, belongs to the technical field of fault diagnosis of power electronic equipment, and aims to realize identification and positioning of an open-circuit fault of a power switch device of the power electronic equipment. The invention adopts the deviation of the expected value and the actual value of the voltage of the interphase electrodes as the diagnosis variable and adopts a screening calculation method to calculate the diagnosis variable, thereby reducing the calculation error and ensuring the accuracy of diagnosis. The diagnostic variables are calculated only by the voltage and current signals existing in the rectifier control system, so that low-cost fault diagnosis can be realized without adding extra hardware. Different voltage thresholds are adopted for different fault characteristic sections, and the voltage thresholds are updated in real time according to the voltage of the direct current side, so that the diagnosis speed is improved, and meanwhile, higher robustness can be ensured. The diagnostic result checking method is adopted to expand the number of diagnosable fault types, so that the invention can realize the fault diagnosis of all power switching devices in the rectifier.
Description
Technical Field
The invention belongs to the technical field of power electronic equipment fault diagnosis, and particularly relates to an open-circuit fault diagnosis method and system for a three-phase three-level rectifier power switching device.
Background
Compared with the traditional two-level converter, the three-level converter has the advantages of higher efficiency, lower current harmonic wave and the like, and is widely applied to high-voltage and high-power occasions. But it is one of the most failure prone links in the converter because it has more power switching devices and these devices operate in high frequency switching states for long periods of time. For the open-circuit fault of the power switching device, the converter system can maintain high performance and continuously operate by adopting fault-tolerant control. And fault diagnosis is a necessary condition for realizing fault-tolerant control, because different fault-tolerant control strategies need to be adopted for different fault switches. Therefore, when the converter has open circuit fault of the power switch device, accurately and quickly identifying and positioning the fault is an important measure for improving the reliability of the converter.
Currently, open-circuit fault diagnosis research on three-level rectifier power switching devices is mainly focused on signal-based methods, model-based methods, and artificial intelligence-based methods. The signal-based method is used for simply calculating and analyzing measurable signals before and after a fault to realize fault location, and can be divided into a current method and a voltage method according to the types of the signals. The current method includes a Pack current vector angle method, a normalized average current method, a current zero zone method and the like. These methods are simple in principle, but slow in diagnosis speed and strongly dependent on load. The diagnosis speed of the voltage method is improved, but the diagnosis cost is high because an additional sensor or a measuring circuit is required to measure the voltage. The method based on the model establishes a mathematical model to calculate the signal, and realizes fault diagnosis by analyzing the residual error of the predicted signal and the actual signal, so that additional hardware is not needed, the diagnosis speed is high, and the diagnosis speed and the robustness are still required to be improved. The method based on knowledge mainly adopts the theories of wavelet transformation, neural network, support vector machine, etc. to process the signals of voltage and current in the circuit and classify the fault, thus realizing the accurate positioning of the fault switch device. Such methods are generally computationally intensive and slow to diagnose.
Therefore, the method for diagnosing the open-circuit fault of the three-phase three-level rectifier power switching device is researched, the speed, the applicability, the robustness and the like of the diagnosis method are improved, and the method has important significance.
Disclosure of Invention
Aiming at the defects or the improvement requirements of the prior art, the invention provides the open-circuit fault diagnosis method and the open-circuit fault diagnosis system for the power switching devices of the three-phase three-level rectifier, which can realize the quick, low-cost and high-robustness identification and positioning of the open-circuit faults of all the power switching devices in the three-level rectifier.
To achieve the above object, according to an aspect of the present invention, there is provided an open fault diagnosis method of a three-phase three-level rectifier power switching device, including:
(1) selecting a desired value of an interphase voltage between X-phase and Y-phase of a k-rectifier at a current timeAnd the actual value V of the phase-to-phase voltageXY(k) The deviation value Δ V of the twoXY(k) As diagnostic variables, among others, XY ═ AB, BC, CA;
(2) obtaining the voltage and current information needed by diagnosis from the rectifier control system, and adopting a screening mode to diagnose the variable delta VXY(k) Calculating;
(3) classifying fault sections according to fault characteristics of the switch when the switch fails at different moments, and updating the diagnosis threshold TH of the current moment aiming at the current fault sectionXY(k);
(4) According to the diagnostic variable Δ VXY(k) And a diagnostic threshold THXY(k) Judging whether the diagnostic variable exceeds a threshold range and the polarity of the diagnostic variable;
(5) identifying and positioning the faults of the internal switching tube according to the judgment result;
(6) and checking the fault diagnosis result, verifying whether the diagnosis result is correct, and correcting the diagnosis result of the fault of the outer switch tube which is possibly diagnosed as the fault of the inner switch tube by mistake to realize the identification and the positioning of the fault of the outer switch tube.
In some alternative embodiments, the composition is prepared byObtaining the expected value of the voltage of the phase-to-phase electrodeByObtaining the actual value V of the voltage of the interphase electrodeXY(k) Wherein V isDC(k) Is the dc side voltage of the rectifier at the present time; sX(k) And SY(k) Switching control signals, S, for X-and Y-phases of the rectifier, respectivelyX(k) Is represented by 1Off SX1And SX2Is conducted and SX3And SX4Off, SX(k) 0 denotes a switch SX2And SX3Is conducted and SX1And SX4Off, SX(k) 1 denotes a switch SX3And SX4Is conducted and SX1And SX2Turning off; eX(k) And EY(k) The voltages of the X phase and the Y phase of the rectifier are respectively the AC side voltages; i isX(k) And IY(k) The AC side currents of the X phase and the Y phase of the rectifier respectively; r is the equivalent resistance of the alternating current side of the rectifier; l is the rectifier AC side inductance; t is sampling interval time, k represents a sampling point at the current moment, and k-1 represents a sampling point at the last moment.
In some alternative embodiments, step (2) comprises:
if no three-phase switch control signal is switched between the sampling points k and k-1, S is satisfiedA(k)=SA(k-1)、SB(k)=SB(k-1) and SC(k)=SCWhen (k-1) is present, thenIf SA(k)=SA(k-1)、SB(k)=SB(k-1) and SC(k)=SCIf one of (k-1) is not satisfied, the value is not adjusted to Δ VXY(k) Calculating the delta V of the current timeXY(k) Considered as zero.
In some alternative embodiments, step (3) comprises:
for the fault diagnosis of the inner switching tube, a fault section is divided into a current zero area and a current non-zero area, and different thresholds are set for different sections:wherein, V is a preset value which is a smaller constant; i isXY(k) 0 represents IXOr IYIn the current zero region, IXY(k) 1 represents IXAnd IYAre all in a current non-zero region, VDC(k) Is the dc side voltage of the rectifier at the present time;
for the definition of the current zero region and the non-zero region, the following definitions are given in consideration of current noise and fluctuation:
In some alternative embodiments, step (4) comprises:
byObtaining an indication of whether the diagnostic variable is outside a threshold range [ -TH [ -XY(k),THXY(k)]And the variable F of its polarityXY(k)。
In some alternative embodiments, step (5) comprises:
internal switching tube fault and variable FXY(k) The corresponding relation between the two is as follows:
at SA2At the time of failure, FAB=1,FBC=0,FCA=-1;
At SA3At the time of failure, FAB=-1,FBC=0,FCA=1;
At SB2At the time of failure, FAB=-1,FBC=1,FCA=0;
At SB3At the time of failure, FAB=1,FBC=-1,FCA=0;
At SC2At the time of failure, FAB=0,FBC=-1,FCA=1;
At SC3At the time of failure, FAB=0,FBC=1,FCA=-1。
In some alternative embodiments, step (6) comprises:
three diagnostic variables Δ V within a preset current period after completion of the fault diagnosisAB(k)、ΔVBC(k) And Δ VCA(k) At least at a certain moment in time, has a value greater than the threshold value TH (k), the diagnosis is correct, using Fcheck1 represents; otherwise, it is finishedΔ V within a predetermined current period after fault diagnosisAB(k)、ΔVBC(k) And Δ VCA(k) If the values of all sampling points do not exceed the threshold TH (k), the result is diagnosed to be wrong, and F is usedcheckDenotes "0", where the threshold th (k) is set to VDC(k)/2+V。
In some alternative embodiments, when FcheckWhen 0, the diagnosis result, FcheckAnd the corresponding relation of the verification result is as follows:
According to another aspect of the present invention, there is provided an open-circuit fault diagnosis system for a three-phase three-level rectifier power switching device, comprising:
a diagnostic variable determination module for selecting a desired value of an interphase voltage between X-phase and Y-phase of the k-rectifier at a current timeAnd the actual value V of the phase-to-phase voltageXY(k) The deviation value Δ V of the twoXY(k) As diagnostic variables, among others, XY ═ AB, BC, CA;
a diagnosis variable calculation module for obtaining the voltage and current information required by diagnosis from the rectifier control system and screening the diagnosis variable DeltaVXY(k) Calculating;
a diagnosis threshold value determining module for classifying the fault sections according to the fault characteristics of the switch when the switch is in fault at different moments, and updating the diagnosis threshold value TH of the current moment aiming at the current fault sectionXY(k);
A polarity determination module for determining a polarity of the output signal based on the diagnostic variable Δ VXY(k) And a diagnostic threshold THXY(k) Judging whether the diagnostic variable exceeds a threshold range and the polarity of the diagnostic variable;
the diagnosis module is used for identifying and positioning the faults of the internal switching tube according to the judgment result;
and the correction module is used for verifying the fault diagnosis result, verifying whether the diagnosis result is correct or not, correcting the diagnosis result of the fault of the outer switch tube which is possibly misdiagnosed as the fault of the inner switch tube, and realizing the identification and the positioning of the fault of the outer switch tube.
According to another aspect of the invention, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method of any of the above.
In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:
(1) through the step (6), the method for checking the diagnosis result can realize the rapid identification and positioning of the open-circuit faults of all the power switching devices in the three-phase three-level rectifier;
(2) through the step (2), the invention adopts a screening calculation method to calculate the voltage deviation of the interphase electrode, thereby reducing the calculation error and improving the diagnosis accuracy;
(3) the invention only needs the existing voltage and current signals in the rectifier control system, thus realizing low-cost fault diagnosis without adding extra hardware;
(4) through the step (3), the threshold value updated in real time in a segmented mode is adopted, the diagnosis speed is improved, and meanwhile high robustness can be guaranteed.
Drawings
Fig. 1 is a topology structure diagram of a three-phase three-level rectifier and a flowchart of a power switch device open-circuit fault diagnosis method thereof according to an embodiment of the present invention;
fig. 2 is a diagram illustrating a diagnosis result of an open-circuit fault of a switching tube in a three-phase three-level rectifier according to an embodiment of the present invention;
fig. 3 is a diagram illustrating a result of diagnosing an open-circuit fault of an external switching tube of a three-phase three-level rectifier according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
Fig. 1 shows an open-circuit fault diagnosis method for a three-phase three-level rectifier power switching device according to an embodiment of the present invention, which includes the following steps:
s1: obtaining information required for diagnosis from a rectifier control system;
three-phase voltage (E) of alternating current side obtained by sampling of three-phase three-level rectifierA(k)、EB(k)、EC(k) Three-phase current (I)A(k)、IB(k)、IC(k) And a DC side voltage (V)DC(k) ) into the control system. The control system obtains the control signal (S) of each phase of power switch device through calculation according to the signals and the stored information of the inductance (L) at the AC side, the equivalent resistance (R) and the likeA(k)、SB(k)、SC(k) And fed to the rectifier so that the rectifier operates as a control target. The control system thus hasAll the information needed for diagnosis, which is used to calculate diagnostic variables and update thresholds.
For the X phase of the rectifier, X is A, B and C, and the four power switching tubes are classified into two outer switching tubes SX1And SX4And two internal switching tubes SX2And SX3Therefore, the rectifier is composed of six outer switch tubes and six inner switch tubes.
S2: calculating voltage deviation of an interphase electrode;
Where k denotes the kth sample.
Actual value V of AB phase voltageAB(k):
Wherein T is the sampling interval time.
Voltage deviation delta V between AB phasesAB(k) The method comprises the following steps When the condition S is satisfiedA(k)=SA(k-1)、SB(k)=SB(k-1) and SC(k)=SC(k-1) in the case of (a),when condition SA(k)=SA(k-1)、SB(k)=SB(k-1) and SC(k)=SCWhen one of the conditions (k-1) is not satisfied,. DELTA.VAB(k)=0。
Similarly, calculating voltage deviation delta V of BC phase-to-phase electrodeBC(k) And voltage deviation delta V of phase to phase CACA(k)。
S3: determining a fault section and updating a threshold value in real time;
in step S3, the failure characteristics of different switches at different times are analyzed, and if the error is not considered: three diagnostic variables Δ V during normal operation of the rectifierAB(k)、ΔVBC(k) And Δ VCA(k) Are all zero; when an open switch fault occurs, the diagnostic variables have different values depending on the faulty switch, current and switch control signals, as shown in table 1 below:
TABLE 1
For the fault diagnosis of the inner switching tube, the specific method for determining the threshold value comprises the following steps:
taking the AB phase as an example, determining a current zero region and a non-zero region:
wherein, IAB(k) 0 represents IAOr IBIn the current zero region, IAB(k) 1 represents IAAnd IBAre all in a current non-zero region, ITHIs a current threshold, and a current amplitude of 5% may be taken.
Similarly, the current zero region and the non-zero region of the BC phase and the CA phase are determined.
Taking phase AB as an example, the main threshold is updated:
where V is a relatively small constant, 2% V may be takenDC。
Similarly, the primary thresholds for the BC and CA phases are updated.
Updating the threshold required for the verification of the diagnosis result:
s4: judging whether the diagnostic variable exceeds the main threshold range and the polarity of the diagnostic variable;
taking AB phase as an example, indicating Δ VAB(k) Whether or not the range [ -TH ] is exceededAB(k),THAB(k)]And the variable F of its polarityAB(k) Comprises the following steps:
similarly, determining the indicator variable F of BC phase and CA phaseBC(k) And FCA(k)。
S5: identifying and locating faults of the inner switching tube;
obtaining FAB(k)、FBC(k) And FCA(k) The internal switching tube fault can then be located according to table 2.
TABLE 2 diagnosis of switching tube faults
S6: and checking the diagnosis result (identifying and positioning the fault of the outer switch tube).
After the diagnosis result of step S5 is obtained, it is judged whether Δ V is presentAB(k)、ΔVBC(k) And Δ VCA(k) Is greater than a threshold th (k). If in 1/8 current period, Δ VAB(k)、ΔVBC(k) And Δ VCA(k) If any of the variables has at least one sample point whose value is greater than the threshold value TH (k), the diagnosis result is correct, using Fcheck1 represents; on the contrary, if in 1/8 current period, Δ VAB(k)、ΔVBC(k) And Δ VCA(k) If the values of all sampling points do not exceed the threshold TH (k), the result is diagnosed to be wrong, and F is usedcheckAnd 0 represents. When F is presentcheckWhen the value is equal to 0, the diagnosis result is corrected to be the corresponding external switchTube failure, as shown in table 3. The result of the diagnosis in step S5 is SA2Open circuit fault, if FcheckIf 1, the result is correct, SA2Open circuit failure; if FcheckIf 0, the result of the diagnosis is incorrect and is corrected to SA1Open circuit failure.
TABLE 3 diagnosis result correction (outer switch tube failure diagnosis)
To more clearly describe this example, the diagnostic results for this example are given in fig. 2 and 3, with the parameters used as shown in table 4.
TABLE 4 parameters used in the examples
As shown in FIG. 2, switch S is turned on and off at 1.03SA2Open circuit fault, after fault Δ VAB(k) Increase rapidly to Δ VAB(k)>THAB(k) Let F stand forAB(k)=1;ΔVCA(k) Rapidly decreases to Δ VCA(k)<-THCA(k) Let F stand forCA(k) -1; and Δ VBC(k) Always within the threshold value, FBC(k) 0. Thus according to Table 2, switch SA2Is diagnosed as an open fault, with a diagnostic time of approximately 0.3 ms. And recognizing SA2Δ V is detected during 1/8 current cycles after an open circuit faultAB(k) Greater than TH (k), i.e. Fcheck1, the diagnosis can therefore be verified as correct according to table 3.
As shown in FIG. 3, switch S is turned on and off at 1.03SA1Open circuit fault, after fault Δ VAB(k) Increase rapidly to Δ VAB(k)>THAB(k) Let F stand forAB(k)=1;ΔVCA(k) Decrease rapidly to deltaVCA(k)<-THCA(k) Let F stand forCA(k) -1; and Δ VBC(k) Always within the threshold value, FBC(k) 0. Thus according to Table 2, switch SA2Is diagnosed as an open fault. But upon recognition of SA2Δ V in 1/8 Current cycle after open FaultAB(k)、ΔVBC(k) And Δ VCA(k) Are all within the threshold range [ -TH (k), TH (k)]In, therefore F check0. The diagnosis result is corrected to S according to Table 3A1Open circuit failure, diagnostic time is about 3 ms.
The results prove that the method can realize the open-circuit fault diagnosis of all power switching devices of the three-phase three-level rectifier, ensure the fault diagnosis speed and accuracy of the inner switching tube which has great influence on the system, and has higher overall diagnosis speed.
The present application further provides a system for diagnosing an open circuit fault of a three-phase three-level rectifier power switching device, comprising:
a diagnostic variable determination module for selecting a desired value of an interphase voltage between X-phase and Y-phase of the k-rectifier at a current timeAnd the actual value V of the phase-to-phase voltageXY(k) The deviation value Δ V of the twoXY(k) As diagnostic variables, among others, XY ═ AB, BC, CA;
a diagnosis variable calculation module for obtaining the voltage and current information required by diagnosis from the rectifier control system and screening the diagnosis variable DeltaVXY(k) Calculating;
a diagnosis threshold value determining module for classifying the fault sections according to the fault characteristics of the switch when the switch is in fault at different moments, and updating the diagnosis threshold value TH of the current moment aiming at the current fault sectionXY(k);
A polarity determination module for determining a polarity of the output signal based on the diagnostic variable Δ VXY(k) And a diagnostic threshold THXY(k) Judging whether the diagnostic variable exceeds a threshold range and the polarity of the diagnostic variable;
the diagnosis module is used for identifying and positioning the faults of the internal switching tube according to the judgment result;
and the correction module is used for verifying the fault diagnosis result, verifying whether the diagnosis result is correct or not, correcting the diagnosis result of the fault of the outer switch tube which is possibly misdiagnosed as the fault of the inner switch tube, and realizing the identification and the positioning of the fault of the outer switch tube.
The specific implementation of each module may refer to the description of the above method embodiment, and the embodiment of the present invention will not be repeated.
The present application further provides a computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements a method of open fault diagnosis for a three-phase three-level rectifier power switching device in method embodiments.
It should be noted that, according to the implementation requirement, each step/component described in the present application can be divided into more steps/components, and two or more steps/components or partial operations of the steps/components can be combined into new steps/components to achieve the purpose of the present invention.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (7)
1. An open-circuit fault diagnosis method for a three-phase three-level rectifier power switching device, comprising:
(1) selecting an expected value of an interphase voltage and an actual value of the interphase voltage between an X phase and a Y phase of the rectifier at the current moment, and taking a deviation value of the expected value and the actual value of the interphase voltage as a diagnosis variable;
(2) acquiring voltage and current information required by diagnosis from a rectifier control system, and calculating diagnosis variables by adopting a screening mode;
wherein, step (2) includes:
if no three-phase switch control signal is switched between the sampling points k and k-1, S is satisfiedA(k)=SA(k-1)、SB(k)=SB(k-1) and SC(k)=SCWhen (k-1) is present, thenIf SA(k)=SA(k-1)、SB(k)=SB(k-1) and SC(k)=SCIf one of (k-1) is not satisfied, the value is not adjusted to Δ VXY(k) Calculating the delta V of the current timeXY(k) Regarded as zero, Δ VXY(k) Representing the deviation between the expected value of the phase-to-phase voltage between the X phase and the Y phase and the actual value of the phase-to-phase voltage, SX(k) Where X is A, B or C is the switching control signal for the X phase of the rectifier at time k, SX(k-1), where X is A, B or C is the switching control signal for rectifier X phase at time k-1,is the expected value of the voltage between the phases, VXY(k) Is the actual value of the phase-to-phase voltage, XY ═ AB, BC, CA;
(3) classifying fault sections according to fault characteristics of the switch when the switch fails at different moments, and updating a diagnosis threshold value of the current moment aiming at the current fault section;
wherein, step (3) includes:
for the fault diagnosis of the inner switch tube, the fault section is divided into a current zero area and a current non-zero area, and different diagnosis thresholds TH are set for different sectionsXY(k):Wherein V is a preset value; i isXY(k) 0 represents IXOr IYIn the current zero region, IXY(k) 1 represents IXAnd IYAre all in a current non-zero region, VDC(k) Is the dc side voltage of the rectifier at the present time;
for the definition of the current zero region and the non-zero region, the following definitions are given in consideration of current noise and fluctuation:
(4) judging whether the diagnosis variable exceeds the threshold range and the polarity of the diagnosis variable according to the diagnosis variable and the diagnosis threshold;
(5) identifying and positioning the faults of the internal switching tube according to the judgment result;
(6) checking the fault diagnosis result, verifying whether the diagnosis result is correct, and correcting the diagnosis result of the fault of the outer switch tube which is possibly diagnosed as the fault of the inner switch tube by mistake to realize the identification and the positioning of the fault of the outer switch tube;
wherein, step (6) includes:
three diagnostic variables Δ V within a preset current period after completion of the fault diagnosisAB(k)、ΔVBC(k) And Δ VCA(k) At least at a certain moment in time, has a value greater than the threshold value TH (k), the diagnosis is correct, using Fcheck1 represents; on the contrary, in the preset current period after the fault diagnosis is finished, the delta V isAB(k)、ΔVBC(k) And Δ VCA(k) If the values of all sampling points do not exceed the threshold TH (k), the result is diagnosed to be wrong, and F is usedcheckDenotes "0", where the threshold th (k) is set to VDC(k)/2+V。
2. The method of claim 1,
byObtaining the expected value of the voltage of the phase-to-phase electrodeByObtaining the actual value V of the voltage of the interphase electrodeXY(k) Wherein V isDC(k) Is the dc side voltage of the rectifier at the present time; sX(k) And SY(k) Are respectively rectifiersX-and Y-phase switching control signals, SX(k) 1 denotes a switch SX1And SX2Is conducted and SX3And SX4Off, SX(k) 0 denotes a switch SX2And SX3Is conducted and SX1And SX4Off, SX(k) 1 denotes a switch SX3And SX4Is conducted and SX1And SX2Turning off; eX(k) And EY(k) The voltages of the X phase and the Y phase of the rectifier are respectively the AC side voltages; i isX(k) And IY(k) The AC side currents of the X phase and the Y phase of the rectifier respectively; r is the equivalent resistance of the alternating current side of the rectifier; l is the rectifier AC side inductance; t is the sampling interval time, k represents the current time sampling point, k-1 represents the last time sampling point, and XY is AB, BC, CA.
4. The method of claim 3, wherein step (5) comprises:
internal switching tube fault and variable FXY(k) The corresponding relation between the two is as follows:
at SA2At the time of failure, FAB=1,FBC=0,FCA=-1;
At SA3At the time of failure, FAB=-1,FBC=0,FCA=1;
At SB2At the time of failure, FAB=-1,FBC=1,FCA=0;
At SB3At the time of failure, FAB=1,FBC=-1,FCA=0;
At SC2At the time of failure, FAB=0,FBC=-1,FCA=1;
At SC3At the time of failure, FAB=0,FBC=1,FCA=-1。
6. an open circuit fault diagnostic system for a three-phase three-level rectifier power switching device, comprising:
the diagnostic variable determining module is used for selecting an expected value of an interphase voltage and an actual value of the interphase voltage between an X phase and a Y phase of the rectifier at the current moment, and taking a deviation value of the expected value and the actual value of the interphase voltage as a diagnostic variable;
the diagnostic variable calculation module is used for acquiring voltage and current information required by diagnosis from the rectifier control system and calculating diagnostic variables in a screening mode, wherein the diagnostic variable calculation module is specifically used for executing the following operations:
if no three-phase switch control signal is switched between the sampling points k and k-1, S is satisfiedA(k)=SA(k-1)、SB(k)=SB(k-1) and SC(k)=SCWhen (k-1) is present, thenIf SA(k)=SA(k-1)、SB(k)=SB(k-1) and SC(k)=SCIf one of (k-1) is not satisfied, the value is not adjusted to Δ VXY(k) Calculating the delta V of the current timeXY(k) Regarded as zero, Δ VXY(k) Representing the deviation between the expected value of the phase-to-phase voltage between the X phase and the Y phase and the actual value of the phase-to-phase voltage, SX(k) Where X is A, B or C is the switching control signal for the X phase of the rectifier at time k, SX(k-1), where X is A, B or C is the switching control signal for rectifier X phase at time k-1,is the expected value of the voltage between the phases, VXY(k) Is the actual value of the phase-to-phase voltage, XY ═ AB, BC, CA;
the diagnostic threshold determining module is used for classifying fault sections according to fault characteristics of the switch when the switch fails at different moments and updating the diagnostic threshold at the current moment aiming at the current fault section;
the diagnostic threshold determination module is specifically configured to perform the following operations: for the fault diagnosis of the inner switch tube, the fault section is divided into a current zero area and a current non-zero area, and different diagnosis thresholds TH are set for different sectionsXY(k):
Wherein V is a preset value; i isXY(k) 0 represents IXOr IYIn the current zero region, IXY(k) 1 represents IXAnd IYAre all in a current non-zero region, VDC(k) Is the dc side voltage of the rectifier at the present time;
for the definition of the current zero region and the non-zero region, the following definitions are given in consideration of current noise and fluctuation:
the polarity determining module is used for judging whether the diagnostic variable exceeds the threshold range and the polarity of the diagnostic variable according to the diagnostic variable and the diagnostic threshold;
the diagnosis module is used for identifying and positioning the faults of the internal switching tube according to the judgment result;
the correction module is used for verifying the fault diagnosis result, verifying whether the diagnosis result is correct or not, correcting the diagnosis result of the fault of the outer switch tube which is possibly misdiagnosed as the fault of the inner switch tube, and realizing the identification and the positioning of the fault of the outer switch tube;
the correction module is specifically configured to perform the following operations:
three diagnostic variables Δ V within a preset current period after completion of the fault diagnosisAB(k)、ΔVBC(k) And Δ VCA(k) At least at a certain moment in time, has a value greater than the threshold value TH (k), the diagnosis is correct, using Fcheck1 represents; on the contrary, in the preset current period after the fault diagnosis is finished, the delta V isAB(k)、ΔVBC(k) And Δ VCA(k) If the values of all sampling points do not exceed the threshold TH (k), the result is diagnosed to be wrong, and F is usedcheckDenotes "0", where the threshold th (k) is set to VDC(k)/2+V。
7. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 5.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202011245559.2A CN112444759B (en) | 2020-11-10 | 2020-11-10 | Open-circuit fault diagnosis method and system for power switch device of three-phase three-level rectifier |
US17/494,847 US11874336B2 (en) | 2020-11-10 | 2021-10-06 | Method and system for diagnosing open-circuit fault of power switching device of three-phase three-level rectifier |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202011245559.2A CN112444759B (en) | 2020-11-10 | 2020-11-10 | Open-circuit fault diagnosis method and system for power switch device of three-phase three-level rectifier |
Publications (2)
Publication Number | Publication Date |
---|---|
CN112444759A CN112444759A (en) | 2021-03-05 |
CN112444759B true CN112444759B (en) | 2021-09-14 |
Family
ID=74736371
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202011245559.2A Active CN112444759B (en) | 2020-11-10 | 2020-11-10 | Open-circuit fault diagnosis method and system for power switch device of three-phase three-level rectifier |
Country Status (2)
Country | Link |
---|---|
US (1) | US11874336B2 (en) |
CN (1) | CN112444759B (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114167303B (en) * | 2021-12-23 | 2023-03-24 | 武汉大学 | Open-circuit fault diagnosis method for power switch device of three-phase three-level rectifier |
CN114113918A (en) * | 2021-12-23 | 2022-03-01 | 国网浙江省电力有限公司经济技术研究院 | Fault detection method and system |
CN114859266B (en) * | 2022-05-30 | 2022-12-16 | 合肥工业大学 | Open-circuit fault diagnosis method for CHB photovoltaic grid-connected inverter system |
CN117872024B (en) * | 2024-03-11 | 2024-05-31 | 国网黑龙江省电力有限公司绥化供电公司 | Fault diagnosis method for electric power supply and distribution system |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105158623B (en) * | 2015-05-22 | 2019-11-05 | 南京航空航天大学 | A kind of three-phase bridge PWM rectifier switching tube open-circuit fault diagnostic method based on current phase angle |
WO2017083527A1 (en) * | 2015-11-13 | 2017-05-18 | Marquette University | An on-line diagnostic method for switch faults in power converters |
AU2016394625B2 (en) * | 2016-02-24 | 2019-08-15 | Mitsubishi Electric Corporation | Converter device |
CN105891658B (en) * | 2016-06-06 | 2019-04-12 | 安徽大学 | A kind of diagnostic method of open-circuit fault of power tubes of inverter |
CN105891659B (en) * | 2016-06-06 | 2019-04-12 | 安徽大学 | A kind of wind electric converter open-circuit fault diagnostic method |
CN107942219B (en) * | 2017-10-23 | 2019-09-10 | 浙江大学 | A kind of open-circuit fault diagnostic method of three-phase four-wire system inverter transistor |
CN109031177B (en) * | 2018-08-15 | 2020-03-31 | 浙江大学 | Diagnosis method considering inverter current sensor fault and power tube open-circuit fault |
CN110426664B (en) * | 2019-08-07 | 2020-09-29 | 浙江大学 | Comprehensive diagnosis method for open-circuit fault and current sensor fault of three-phase three-wire system inverter power tube with two current sensors |
CN111624514B (en) * | 2020-07-02 | 2022-08-26 | 南京师范大学 | Method for diagnosing short-circuit and open-circuit faults of switching tube of three-level rectifier |
-
2020
- 2020-11-10 CN CN202011245559.2A patent/CN112444759B/en active Active
-
2021
- 2021-10-06 US US17/494,847 patent/US11874336B2/en active Active
Also Published As
Publication number | Publication date |
---|---|
US11874336B2 (en) | 2024-01-16 |
CN112444759A (en) | 2021-03-05 |
US20220146592A1 (en) | 2022-05-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN112444759B (en) | Open-circuit fault diagnosis method and system for power switch device of three-phase three-level rectifier | |
CN106885966B (en) | A kind of MMC power device open-circuit fault diagnostic method | |
CN106019056B (en) | Real-time detection method for open-circuit fault of three-phase rectifier power tube | |
WO2021184820A1 (en) | Two-level three-phase voltage source inverter bridge arm open-circuit fault diagnosis method | |
CN110110461B (en) | Method for estimating IGBT (insulated Gate Bipolar translator) parameters in MMC (Modular multilevel converter) based on Kalman filtering algorithm | |
CN110187209B (en) | Modular multilevel converter submodule fault detection method, system and medium | |
CN108828387B (en) | MMC submodule open-circuit fault integrated diagnosis method | |
CN110426664B (en) | Comprehensive diagnosis method for open-circuit fault and current sensor fault of three-phase three-wire system inverter power tube with two current sensors | |
CN107589335A (en) | A kind of diagnostic method of MMC submodules open-circuit fault of power tubes | |
CN109085460B (en) | Ultra-high voltage direct current transmission line fault single-end diagnosis method based on transient quantity monitoring | |
CN110988742A (en) | Open-circuit fault diagnosis method for modular multilevel converter based on quartile | |
CN109725213A (en) | Buck converter fault detection method based on reverse Kalman filter | |
CN108872772B (en) | MMC submodule open-circuit fault detection method based on hybrid nuclear support tensor machine | |
CN111707973A (en) | Open-circuit fault diagnosis method for modular multilevel converter based on Grabbs criterion | |
CN113358997A (en) | MMC submodule IGBT open-circuit fault diagnosis method based on fault model | |
CN114236374A (en) | Real-time diagnosis method for open circuit fault of rectifier | |
CN109738778B (en) | Inverter open circuit diagnosis method and device, terminal equipment and computer readable medium | |
KR20210142883A (en) | Multi-switch open-fault diagnosis metohd of 3-phase pwm converter using ai and device for performing the same | |
KR20150063920A (en) | Detecting shorted diodes | |
CN112526397A (en) | Open-circuit fault diagnosis method for neutral point clamped single-phase three-level inverter | |
CN114062883B (en) | IGBT open-circuit fault diagnosis method and system for T-type three-level inverter | |
CN111983508A (en) | T-type three-phase four-wire rectifier fault real-time detection and positioning method and system | |
Al-Sheikh et al. | A sensor fault diagnosis scheme for a DC/DC converter used in hybrid electric vehicles | |
CN114545133B (en) | Fault diagnosis method of single-phase cascade H-bridge rectifier based on current detection | |
CN115343656A (en) | Fault hypothesis-based open-circuit fault diagnosis method for switching tube in three-level rectifier |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |